|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Alloys and Compounds for Thermoelectric and Solar Cell Applications IX
||Optimization of n- and p-type Mg2X (X: Si, Ge, Sn): Understanding the Impact of Mg on the Thermoelectric Performance and the Change of the Valence Bands Under Solid Solution Formation
||Johannes De Boor, Hasbuna Kamila, Mohammad Yasseri, Aryan Sankhla, Eckhard Müller
|On-Site Speaker (Planned)
||Johannes De Boor
Among the materials studied for thermoelectric applications, Mg2X (X: Si, Ge, Sn) and their solid solutions are of very high interest as their constitutive elements are abundant, non-toxic and mostly cheap. We have investigated the influence of excess or deficient Mg on the thermoelectric performance of n-type Mg2(Si,Sn) by in situ transport measurements and microstructural analysis of annealed samples. It will be shown that the Mg content has a strong impact on the demixing kinetics of the solid solutions. In-depth analysis of the transport data indicates an increased electron-phonon scattering for Mg-deficient samples as well as an increasing impact of grain boundary scattering.
We will also show that the p-type material can be improved by solid solution formation of Mg2Ge with Mg2Si and Mg2Sn, making use of an advantageous, temperature dependent band structure of Mg2Ge and a thermal conductivity reduction due to alloying.